1. Field of the Invention
This invention relates to a sound suppression system for an engine air supply conduit for watercraft.
2. Related Art
This invention relates to an engine air supply duct for watercraft which provides a supply of air from outside the watercraft hull or enclosure to an internal combustion engine used for propulsion of the watercraft that is mounted inside a compartment within or defined by the watercraft hull.
This invention is particularly adapted for use with smaller watercraft that are intended to be operated by a driver that straddles a bench type seat extending along the upper longitudinal part of the watercraft and wherein an internal combustion engine is mounted inside the watercraft arranged to drive a jet pump mounted at the stern of the watercraft for propelling the craft in water. Such watercraft include an air supply system to supply air from outside the watercraft hull to the interior thereof for supply of combustion air to the internal combustion engine.
In accordance with prior art techniques, air intake noise in the air supply conduit and internal combustion engine noise generated inside the watercraft hull escaping through the air intake conduit detract from pleasurable operation of the watercraft.
The present invention is intended to attenuate air intake noise at the entrance to the air supply conduit as well as noise emanating from the conduit between the inside and outside of the watercraft hull.
An air supply system for watercraft includes an air supply conduit for introducing outside air to the inside of the watercraft hull that encloses an internal combustion engine for propelling the watercraft, wherein the air supply conduit includes a noise damping resonating chamber along its length. The air supply conduit also may include a noise suppressor at its inlet end in combination with the resonating chamber.
A plurality of air supply conduits including the aforesaid noise attenuating elements may be utilized. The air supply conduits are oriented and configured to enhance drainage of water from the conduits, including the resonating chambers, and may be branched to minimize taking on water through the conduits in the event that the watercraft capsizes and is righted by rotation about its longitudinal axis.
The inlet noise attenuator may be configured in the form of a flow divider network of smaller honeycomb-like cells for dividing the inlet into a plurality of small, short conduits that effectively attenuate noise emanating from the interior of the air supply conduit (and the interior of the watercraft hull) to ambient.